Quay structure and method for constructing the quay structure

Abstract

To provide a quay wall structure capable of reducing the load applied onto the support structure and improving the rigidity of the wall while suppressing the increase in the amount of steel.SOLUTION: The quay wall structure includes: a first steel pipe row that includes a plurality of steel pipe piles that are connected to a steel sheet pile wall above the ground, and a first steel pipe sheet pile which is placed at a ratio of 1 to the plurality of steel pipe piles, connected to the steel sheet pile wall above the underground and arranged at the sea side of the steel sheet pile wall at intervals consistent with the planar concaves and convexes shape of the steel sheet pile wall; and a second steel pipe row in which at least one steel pipe pile sheet including a second steel pipe sheet piles that function at least as part of the support pile structure is arranged in the direction intersecting the extension direction of the steel sheet pile wall from the first steel pipe sheet.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a quay structure and a method for constructing a quay structure. [Background technology]

[0002] In a quay wall structure, a steel retaining wall is cast deeper than the seabed to resist the back earth pressure. Steel sheet piles and steel pipe sheet piles are generally used as the steel material for the retaining wall because they are easy to cast into the ground. When the water depth is large, the steel sheet piles and steel pipe sheet piles alone are insufficient to resist the back earth pressure, so a tie rod structure installed at the back and a pier structure installed at the front are used to support the horizontal force of the wall head and resist the back earth pressure. When a pier is added in front of the revetment normal line, a jacket structure for the front pier is adopted as an economical and rapid construction method. However, the retaining wall is not directly connected by the jacket, and the back earth pressure acting on the retaining wall is only transmitted to the jacket structure built on the sea side. Therefore, steel material is required for both the retaining wall and the pier, and the amount of steel increases, which tends to reduce the economic efficiency.

[0003] In response to this, Patent Document 1 proposes a technique for constructing an arch-shaped earth retaining wall that is convex toward the sea using sheet-like members, such as straight steel sheet piles. In this case, the backside earth pressure is transmitted to the legs of the jacket structure as horizontal tension of the earth retaining wall. By utilizing tension rather than bending rigidity of the earth retaining wall, it is possible to construct a steel sheet pile wall that can resist backside earth pressure while suppressing an increase in the amount of steel material due to an increase in the cross section or the addition of wale construction. In addition, Patent Document 2 proposes a steel wall that is constructed by combining hat-shaped steel sheet piles and steel pipes. Patent Document 3 proposes a technique for reinforcing a steel sheet pile wall with steel pipes or H-shaped steel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-194867 A [Patent Document 2] International Publication No. 2011 / 142367 [Patent Document 3] International Publication No. 2013 / 164885 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of a steel sheet pile wall as described in Patent Document 1, the back earth pressure transmitted by tension from the earth retaining wall is resisted only by the support structure including the jacket structure, and the load borne by the support structure becomes excessive, which results in an increase in the amount of steel in the support structure, which is not economical and also increases the difficulty of construction. The techniques in Patent Documents 2 and 3 allow the construction of a steel wall with improved rigidity while suppressing the increase in the amount of steel, but do not describe a method of installing a support structure such as a jacket structure when the resistance against the back earth pressure is insufficient. Therefore, even when planning to deepen the existing revetment or reinforce it against earthquakes, a design was made in which a wall structure and a pier structure such as a jacket were newly installed on the sea side of the existing wall, and only the newly installed structure was designed to resist the back earth pressure, etc.

[0006] Therefore, the present invention aims to provide a quay wall structure and a method for constructing a quay wall structure that can utilize existing walls to improve the rigidity of the wall body while suppressing an increase in the amount of steel used, and also reduce the load borne by the supporting structure. [Means for solving the problem]

[0007] [1] A wharf structure comprising: a plurality of steel pipe piles connected to a steel sheet pile wall at a portion above the underground portion; and a first steel pipe sheet pile arranged in a ratio of one for each of the plurality of steel pipe piles and connected to the steel sheet pile wall at a portion above the underground portion, the first steel pipe row being arranged on the sea side of the steel sheet pile wall at an interval that matches the unevenness of the planar shape of the steel sheet pile wall; and a second steel pipe row in which at least one steel pipe sheet pile including a second steel pipe sheet pile functioning as at least a part of a support pile structure is arranged in a direction intersecting from the first steel pipe sheet pile to the extension direction of the steel sheet pile wall. [2] The quay structure described in [1], further comprising a retaining pile structure located on the seaward side of the support pile structure, and a connecting member connecting the support pile structure to the retaining pile structure. [3] The quay structure described in [2], wherein the support pile structure includes a second steel pipe sheet pile and a first jacket leg that fits onto the outside of the head of the second steel pipe sheet pile, the bracing pile structure includes a bracing pile and a second jacket leg that fits onto the outside of the head of the bracing pile, and the connecting member includes a first connecting member that is arranged between the first jacket leg and the second jacket leg. [4] The quay wall structure described in [3], wherein the support pile structure includes an engaging member that fits into the inside of the head of the first steel pipe sheet pile, and the connecting member includes a second connecting member that is arranged between the first jacket leg and the engaging member. [5] A quay wall structure as described in [3] or [4], wherein at the head of the second steel pipe sheet pile, no joint is formed between the second steel pipe sheet pile and an adjacent steel pipe sheet pile, and the first jacket leg is fitted from the outside into the part where no joint is formed. [6] A quay wall structure described in any one of [1] to [5], wherein a stopper protrudes from the peripheral surface of the steel pipe sheet pile in a joint space enclosed by fitting joints between the first steel pipe sheet pile and the steel pipe sheet pile included in the second steel pipe row, or between the steel pipe sheet piles included in the second steel pipe row, and the joint space is filled with a filler material. [7] A method for constructing a quay structure comprising the steps of: constructing a first steel pipe row on the sea side of a steel sheet pile wall by arranging a plurality of steel pipe piles and a first steel pipe sheet pile arranged one for each of the plurality of steel pipe piles at intervals that match the unevenness of the planar shape of the steel sheet pile wall, connecting the steel sheet pile wall and the first steel pipe row above an underground portion, constructing a second steel pipe row by connecting at least one steel pipe sheet pile to the first steel pipe sheet pile, and incorporating a second steel pipe sheet pile included in the second steel pipe row into a support pile structure. [8] The method for constructing a quay structure according to [7], wherein the step of incorporating the second steel pipe sheet pile into the support pile structure includes a step of fitting a first jacket leg to the outside of a head of the second steel pipe sheet pile, and further includes a step of driving a backing pile on the sea side of the first steel pipe sheet pile using as a guide the second jacket leg connected to the first jacket leg via a connecting member. [9] A method for constructing a wharf structure as described in [7], further comprising the steps of: installing a first jacket leg, a second jacket leg located seaward of the first jacket leg, and connecting members connecting the first jacket leg to the second jacket leg; and driving supporting piles using the second jacket leg as a guide, wherein the step of incorporating the second steel pipe sheet pile into the supporting pile structure includes the step of driving the first steel pipe sheet pile using the first jacket leg as a guide. Effect of the Invention

[0008] According to the above-mentioned configuration, the steel sheet pile wall having bending resistance against back earth pressure, the first steel pipe row arranged in the extension direction of the steel sheet pile wall, and the second steel pipe row arranged in the direction intersecting the steel sheet pile wall behave as a wall body integrally, so that a wharf structure having a desired bending rigidity against back earth pressure can be easily constructed. In addition, the rotation moment generated in the retaining wall by the back earth pressure can be resisted by the vertical ground reaction force received by the second steel pipe row. Therefore, the load borne by the supporting structure can be reduced while suppressing the increase in the amount of steel material. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view of a quay wall structure according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a diagram showing a modification of the example shown in FIG. 2. [Figure 4] FIG. 2 shows examples of joints that can be used in the quay wall structure shown in FIG. 1. [Diagram 5] This is a graph showing the relationship between cross-sectional performance and material costs when steel pipes are arranged discretely, in comparison with when they are arranged continuously (steel pipe sheet pile wall). [Figure 6] 1 is a graph showing the results of calculating the displacement with respect to the total load by the finite element method (FEM) between an example of the present invention and a comparative example. [Figure 7]13 is a graph showing the results of frame calculation of the load sharing rate of a wall when the number of steel pipe sheet piles constituting a steel pipe row arranged in a direction intersecting the wall is changed for an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and duplicated explanations will be omitted.

[0011] Fig. 1 is a plan view of a quay wall structure according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As shown in the figure, the quay wall structure 1 includes a steel sheet pile wall 2, a first steel pipe row 3 arranged on the sea side of the steel sheet pile wall 2, a second steel pipe row 4 arranged from a steel pipe sheet pile 31 (first steel pipe sheet pile) included in the first steel pipe row 3 toward the sea side, i.e., in a direction intersecting the extension direction of the steel sheet pile wall 2, and a support pile structure 5 including a steel pipe sheet pile 41 (second steel pipe sheet pile) located at an end of the second steel pipe row 4 opposite to the steel sheet pile wall 2 and a jacket leg 52 fitted to the outside of the head of the steel pipe sheet pile 41.

[0012] In this specification, a steel pipe row is composed of one or more steel pipe piles or steel pipe sheet piles. A steel pipe sheet pile has at least one joint extending in the longitudinal direction of the steel pipes arranged on the circumferential surface of the steel pipe pile, and adjacent steel pipe sheet piles are connected to each other by engaging the joints.

[0013] The first steel pipe row 3 includes a plurality of steel pipe piles 32 and steel pipe sheet piles 31 (first steel pipe sheet piles), and one steel pipe sheet pile 31 is arranged for each of the plurality of steel pipe piles 32. The plurality of steel pipe piles 32 and the steel pipe sheet piles 31 are arranged at intervals that match the unevenness of the planar shape of the steel sheet pile wall 2, and are connected to the steel sheet pile wall 2 above the underground portion using connecting members 33. In the illustrated example, the plurality of steel pipe piles 32 are not connected to each other, and the plurality of steel pipe piles 32 are not connected to the steel pipe sheet piles 31. The joints 311 of the steel pipe sheet piles 31 are used to connect to the steel pipe sheet piles of the second steel pipe row 4.

[0014] The second steel pipe row 4 includes at least one steel pipe sheet pile including a steel pipe sheet pile 41 (second steel pipe sheet pile). In the illustrated example, in addition to the steel pipe sheet pile 41, two steel pipe sheet piles 42 and 43 are included, and the second steel pipe row 4 is composed of the three steel pipe sheet piles 41, 42, and 43. The steel pipe sheet pile 43 closest to the first steel pipe row 3 is connected to the steel pipe sheet pile 31 by engaging a joint 431 with a joint 311 of the steel pipe sheet pile 31 included in the first steel pipe row 3. In the same manner, the steel pipe sheet pile 42 is connected to the steel pipe sheet pile 43, and the steel pipe sheet pile 41 is connected to the steel pipe sheet pile 42. In this way, the second steel pipe row 4 is arranged in a direction intersecting the extension direction of the steel sheet pile wall 2 from the steel pipe sheet pile 31 (first steel pipe sheet pile).

[0015] In other examples, the number of steel pipe sheet piles constituting the second steel pipe row 4 may be less than that in the illustrated example. For example, a steel pipe sheet pile row may be formed by directly connecting a steel pipe sheet pile 31 (first steel pipe sheet pile) and a steel pipe sheet pile 41 (second steel pipe sheet pile) functioning as part of the support pile structure, and no intermediate steel pipe sheet piles may be included. Alternatively, the number of steel pipe sheet piles constituting the second steel pipe row 4 may be more than that in the illustrated example.

[0016] In this embodiment, the steel pipe sheet pile 41 (second steel pipe sheet pile) located at the end of the second steel pipe row 4 opposite to the steel sheet pile wall 2 functions as part (support pile 51) of the support pile structure 5 together with the jacket leg 52. In the illustrated example, the quay wall structure 1 further includes a bracing pile structure 6 located on the seaward side of the support pile structure 5, and a beam 7 which is a connecting member connecting the support pile structure 5 to the bracing pile structure 6. The bracing pile structure 6 includes a bracing pile 61 and a jacket leg 62 which fits onto the outside of the head of the bracing pile 61, and the beam 7 is disposed between the jacket legs 52, 62.

[0017] Fig. 3 is a diagram showing a modified example of the example shown in Fig. 2. In the example shown in Fig. 3, the support pile structure 5 further includes a fitting member 53 (also called stabbing) that fits inside the head of the steel pipe sheet pile 31 (first steel pipe sheet pile), and the beam 7 includes a portion (first connecting member) disposed between the jacket legs 52, 62, and a portion (second connecting member) disposed between the jacket leg 52 and the fitting member 53.

[0018] 2, in the support pile structure 5, the jacket leg 52 fits into the head of the steel pipe sheet pile 41 (support pile 51). The steel pipe sheet pile 41 is connected to an adjacent steel pipe sheet pile by, for example, a joint as described below, but at the head of the steel pipe sheet pile 41 to which the jacket leg 52 fits outside, a joint does not need to be formed between the adjacent steel pipe sheet pile. By leaving a gap between the steel pipe sheet pile 41 and the adjacent steel pipe sheet pile and fitting the jacket leg 52 from the outside into the part where no joint is formed, construction of the jacket leg 52 becomes easier.

[0019] FIG. 4 is a diagram showing an example of a joint that can be used in the quay wall structure shown in FIG. 1. In the illustrated example, a joint 401 between two steel pipe sheet piles 40 includes a pair of female joint members 401A protruding from the peripheral surface of one steel pipe sheet pile and a pair of male joint members 401B protruding from the peripheral surface of the other steel pipe sheet pile. A filler material 402 is filled in a joint space surrounded by fitting the joints 401 between the steel pipe sheet piles, that is, a space surrounded by the female joint member 401A, the male joint member 401B and the peripheral surfaces of each steel pipe sheet pile 40. Specifically, the female joint member 401A and the male joint member 401B are formed of, for example, angle steel. The filler material 402 can be mortar, cement, concrete, or the like. Such a joint can transmit horizontal compressive loads and shear loads between the steel pipe sheet piles.

[0020] Furthermore, in this embodiment, the joint 401 has shear stoppers 403A, 403B. The shear stoppers 403A, 403B protrude from the peripheral surface of the steel pipe sheet pile between a pair of female joint members 401A or between a pair of male joint members 401B into the joint space and are fixed to the filler material 402, so that the vertical shear load is more reliably transmitted between the steel pipe sheet piles. By disposing the shear stoppers 403A, 403B, it is possible to more reliably prevent the occurrence of positional displacement due to vertical shear between the two steel pipe sheet piles 40, and to make the first steel pipe row 3 and the second steel pipe row 4 behave as an integral wall body. The shear stoppers 403A, 403B may be, for example, ribs extending in the horizontal direction as shown in the figure, or may be beads protruding in a point-like shape.

[0021] The joints 401 as described above may be arranged not only between the steel pipe sheet piles constituting the second steel pipe row 4, but also between the steel pipe sheet piles 31 of the first steel pipe row 3 and the steel pipe sheet piles of the second steel pipe row 4. Although not shown, the integrity of the wall W may be improved by fixing the heads of the steel pipe piles and steel pipe sheet piles constituting the first steel pipe row 3 and the steel pipe sheet piles constituting the second steel pipe row 4 by copings.

[0022] Next, an example of a method for constructing a quay wall structure according to this embodiment will be described briefly. First, a first steel pipe row 3 is constructed by arranging a plurality of steel pipe piles 32 and steel pipe sheet piles 31 (first steel pipe sheet piles) at intervals that match the unevenness of the planar shape of the steel sheet pile wall 2 on the sea side of the steel sheet pile wall 2. Next, a second steel pipe row 4 is constructed by connecting at least one steel pipe sheet pile to the steel pipe sheet pile 31 included in the first steel pipe row 3. In the example shown in Fig. 1, the second steel pipe row 4 is constructed by sequentially connecting a steel pipe sheet pile 43, a steel pipe sheet pile 42, and a steel pipe sheet pile 41 to the steel pipe sheet pile 31. For example, the steel pipe sheet piles of the second steel pipe row 4 may be driven after driving all the steel pipe piles 32 and steel pipe sheet piles 31 of the first steel pipe row 3, or the steel pipe sheet piles of the second steel pipe row 4 may be driven in parallel with or before or after the driving of the steel pipe piles 32 and other steel pipe sheet piles 31 after driving the steel pipe sheet piles 31. Furthermore, the steel pipe sheet piles of the second steel pipe row 4 do not necessarily have to be driven in sequence from the side closer to the first steel pipe row 3. For example, the steel pipe sheet pile 41 (second steel pipe sheet pile) that functions as a part of the support pile structure may be driven first, and the other steel pipe sheet piles of the second steel pipe row 4 may be driven while adjusting their positions so as to connect between the steel pipe sheet pile 41 and the steel pipe sheet pile 31 (first steel pipe sheet pile) of the first steel pipe row 3.

[0023] After the steel pipe sheet pile 41 (support pile 51) is driven, a jacket structure including the jacket leg 52, the beam 7, and the jacket leg 62 is installed on the steel pipe sheet pile 41, and the back pile 61 is driven using the jacket leg 62 as a guide. As another example, the jacket structure (jacket leg 52, the beam 7, and the jacket leg 62) may be installed in advance using temporary piles, and the steel pipe sheet pile 41 and the back pile 61 may be driven using the jacket legs 52, 62 as guides. By any of the above steps, the steel pipe sheet pile 41 located at the end of the second steel pipe row 4 opposite to the steel sheet pile wall 2 is incorporated into the support pile structure 5 as the support pile 51. A superstructure (not shown) constituting the apron part of the quay may be installed above the jacket structure. The above steps may be carried out as reinforcement work for an existing steel sheet pile wall 2, and a quay structure including a first steel pipe row 3 and a second steel pipe row 4 in addition to the steel sheet pile wall 2 may be constructed, or the step of constructing the steel sheet pile wall 2 may be carried out before the above steps.

[0024] The Vibro Hammer method is often used when driving steel pipe piles and steel pipe sheet piles into port structures such as quays and piers. The Vibro Hammer method is a method in which steel material is vibrated and driven into the ground. In order to prevent damage to the steel pipe during construction, the Vibro Hammer method requires a certain level of plate thickness relative to the steel pipe diameter. For example, the Vibro Hammer Method Technology Research Group has set standard values ​​for the ratio of plate thickness t to steel pipe diameter D as t / D≧1.0% or more for steel pipe piles and t / D≧1.4% or more for steel pipe sheet piles. The reason why the standard value for steel pipe sheet piles is higher is because the joints may become a resistance during construction.

[0025] On the other hand, the cross-sectional properties such as the moment of inertia and section modulus of a wall including steel pipes can be improved more effectively by increasing the diameter of the steel pipes than by increasing the plate thickness. When a wall is constructed by connecting steel pipe sheet piles with joints, there is a restriction that the steel pipe sheet piles must be arranged continuously in the extension direction of the wall via joints, and in addition, as described above, the plate thickness needs to be made larger relative to the steel pipe diameter. In contrast, when the steel pipes arranged in the extension direction of the wall are not connected as in this embodiment, and the first steel pipe row is constructed of steel pipe piles 32 except for the steel pipe sheet pile 31 connected to the second steel pipe row, the plate thickness can be made smaller than that of a steel pipe sheet pile of the same diameter even if the diameter of the steel pipe pile is increased, and the steel pipe piles do not need to be arranged continuously, so that the cross-sectional properties can be efficiently improved relative to the amount of steel material.

[0026] In this embodiment, the steel pipe sheet piles 31 and the steel pipe piles 32 are arranged at intervals that match the unevenness of the planar shape of the steel sheet pile wall 2, based on the idea of ​​providing the steel sheet pile wall with an earth retaining function while providing the steel pipe piles with the necessary bearing strength. For example, in the case of a U-shaped steel sheet pile with a width of 400 mm, the unevenness pitch is 800 mm, so that the steel pipe sheet piles 31 and the steel pipe piles 32 with a diameter of 1200 mm are arranged at a pitch of 1600 mm to match this, as shown in FIG. 1. In the example of FIG. 1, the steel pipe sheet piles 31 and the steel pipe piles 32 are arranged at positions corresponding to the concave parts of the planar shape of the steel sheet pile wall 2, and are connected to the web parts of the steel sheet piles located at the convex parts of the planar shape by connecting members 33, specifically steel plates. The above-mentioned arrangement is possible by setting the diameter of the steel pipe sheet piles 31 and the steel pipe piles 32 to 800 mm or more, which is more than twice the width of the U-shaped steel sheet pile (400 mm).

[0027] Figure 5 is a graph showing the relationship between the cross-sectional performance and material cost when steel pipes are arranged discretely, in comparison with the case of continuous arrangement (steel pipe sheet pile wall). The graph in Figure 5 shows the relationship between the moment of inertia per unit width and the material cost per meter of length when steel pipes are arranged at a pitch of 1600 mm in a steel sheet pile wall composed of 400 mm wide U-shaped steel sheet piles as in the above example. For each example, the moment of inertia was calculated taking into account only the rigidity of the steel pipes. In addition, the material cost was calculated based on the dimensions of each member and the construction price. The joints of the steel pipe sheet piles were PP type as specified in JIS A5530. In addition, multiple steel pipe diameters were set for each example, and the plate thickness was set to the minimum value that satisfies t / D ≧ 1.0% for steel pipe piles and t / D ≧ 1.4% for steel pipe sheet piles, assuming that the construction will be performed using the vibro hammer method.

[0028] For example, in the case of a steel pipe sheet pile wall using steel pipes with a diameter of 1000 mm and a plate thickness of 14 mm (the pitch of the steel pipes is the steel pipe diameter + joint length), the moment of inertia per unit width is 4.22 x 10 5 (cm 4) In contrast, when the steel pipes are arranged discretely as in this embodiment, in order to construct a wall having the same geometrical moment of inertia, it is sufficient to arrange steel pipes with a diameter of 1200 mm and a thickness of 12 mm at a pitch of 1600 mm. As a result, it is possible to reduce the material cost by about 40% compared to the case of steel pipe sheet piles while maintaining the same geometrical moment of inertia. This is also true for other examples of steel pipe diameters, and by discretely arranging steel pipes using an existing steel sheet pile wall as described above, for example, it is possible to construct a wall that satisfies the required cross-sectional performance with less material cost than a steel pipe sheet pile wall.

[0029] In addition, in this embodiment, the first steel pipe row 3 is arranged on the sea side of the steel sheet pile wall 2 that receives back earth pressure from the ground G, and the second steel pipe row 4 is further arranged from the steel pipe sheet pile 31 of the first steel pipe row 3 toward the sea side, so that the steel sheet pile wall 2, the first steel pipe row 3, and the second steel pipe row 4 can be integrally behaved as a U-shaped wall body W (shown surrounded by a chain line) against the ground G. The second moment of area of ​​the wall body W is larger than that of, for example, the case where only the first steel pipe row 3 parallel to the steel sheet pile wall 2 is constructed, and can be easily adjusted by the number of steel pipe sheet piles that constitute the second steel pipe row 4, so that the quay wall structure 1 having the desired bending rigidity against the back earth pressure can be easily constructed. In addition, the rotation moment generated in the steel sheet pile wall 2 by the back earth pressure can be resisted by the vertical ground reaction force received by the second steel pipe row 4. Therefore, the load borne by the support structure can be reduced while suppressing an increase in the amount of steel material.

[0030] Furthermore, in this embodiment, since the steel pipe sheet piles of the second steel pipe row 4 do not constitute an earth retaining wall, it is not necessary to connect the steel pipe sheet piles constituting the second steel pipe row 4 with each other and between the steel pipe sheet piles of the second steel pipe row 4 and the steel pipe sheet pile 31 of the first steel pipe row 3 with joints over the entire length in the depth direction. Therefore, as described above, no joints are formed in the upper part between the steel pipe sheet pile 41 located at the end of the second steel pipe row 4 and the adjacent steel pipe sheet pile, and a gap is left around the steel pipe sheet pile 41, which makes it easier to install the jacket leg 52.

[0031] One embodiment of the present invention as described above can be applied when planning to deepen or reinforce an existing revetment. Conventionally, in such cases, a new wall structure is constructed on the seaward side of the existing wall, and the space between the existing wall and the new wall is filled in. In order to take into account the increase in earth pressure due to the deepening and earthquake load as external forces, the new wall needs to have a higher bending rigidity than the existing wall. As a result, the cross section of the steel material that constitutes the wall structure needs to be enlarged, which increases costs. Furthermore, since filling work is also required, the total construction cost tends to be high.

[0032] On the other hand, when this embodiment is applied to deepening or seismic reinforcement of a steel sheet pile wall constructed as an existing revetment, the insufficient rigidity is compensated for by arranging steel pipe piles and steel pipe sheet piles discretely in the extension direction of the wall body at positions adjacent to the existing wall. Although it is possible to construct a steel pipe sheet pile wall as a wall structure with high bending rigidity, the steel pipe sheet piles need to be arranged continuously, not discretely, since the steel pipe sheet pile wall itself is required to function as a wall. In this embodiment, the existing steel sheet pile wall already exists as a surface that receives earth pressure, and the steel pipe piles and steel pipe sheet piles are arranged to compensate for the insufficient rigidity, so that the bending rigidity can be rationally compensated for. In addition, since the process of constructing a new wall on the sea side is omitted, no landfill work is required, and landfill costs can be reduced.

[0033] In addition, when connecting steel pipe rows in a direction intersecting the extension direction of the wall body to reinforce an existing wall, it is difficult to attach joints to the existing wall itself on-site, but when constructing a steel pipe row separately from the existing wall as in this embodiment, it is possible to easily connect the steel pipe rows in a direction intersecting the extension direction of the wall body by making some of the steel pipe piles that make up the steel pipe row into steel pipe sheet piles with joints attached. By connecting this steel pipe row to the jacket, the load sharing by the U-shaped wall body W is increased and the load sharing by the jacket is reduced, making it possible to construct a more economical pier structure. EXAMPLES

[0034] FIG. 6 is a graph showing the results of calculating the displacement with respect to the total load by the finite element method (FEM) between a quay wall structure (Example) including a first steel pipe row arranged in the extension direction of the wall and a second steel pipe row arranged in a direction intersecting therewith as in one embodiment of the present invention described above, and a quay wall structure (Comparative Example) including only a steel pipe row arranged in the extension direction of the wall. In the Examples and Comparative Examples described below, in order to compare the wall shapes, the walls were constructed by connecting steel pipe sheet piles having a diameter of 1100 mm and a pipe thickness of 12 mm with joints. In the Example, nine steel pipe sheet piles were connected to each other to construct a wall with a width of 10 m (first steel pipe row), and three steel pipe sheet piles arranged in a direction perpendicular to the extension direction of the wall were connected to the steel pipe sheet piles at both ends (second steel pipe row). The steel pipe sheet piles located at the ends of the second steel pipe row are connected to the bail structure via jacket legs and beams. On the other hand, in the comparative example, nine steel pipe sheet piles were connected to each other to construct a 10m-wide wall, and the steel pipe rows were not arranged perpendicular to the extension direction of the wall, but the steel pipe sheet piles at both ends of the wall were connected to the pier structure via jacket legs and beams. In both the example and the comparative example, copings were installed at the heads of the steel pipe sheet piles that make up the wall and the steel pipe rows, so that vertical displacement would not occur between the steel pipe sheet piles.

[0035] In both the example and the comparative example, the ground surface on the land side coincided with the upper end of the steel pipe sheet pile, and the embedded depth of the support pile and the backing pile based on the ground surface on the land side was 46.3 m, and the embedded depth of the steel pipe sheet pile was 32.5 m. The distance from the upper end of the steel pipe sheet pile to the seabed was 16.9 m. The lower ends of the steel pipe sheet pile and the backing pile to which the jacket leg was attached were pin supports that did not cause vertical displacement, and the passive earth pressure from the sea side acting on the underground part of the wall was set. In addition, the length of the jacket leg of the support pile structure was 5.4 m. Under the above conditions, the relationship between the total load of the active earth pressure from the land side acting on the wall and the displacement occurring at the upper end (pier shoulder) of the backing pile structure is shown in the graph in Figure 6. As shown in the graph, the results of the FEM calculations showed that in a quay wall structure (embodiment) including a first row of steel pipes arranged in the extension direction of the wall and a second row of steel pipes arranged in a direction intersecting the first row, the displacement for the same total load was reduced by approximately 17% compared to a quay wall structure (comparison example) including only a row of steel pipes arranged in the extension direction of the wall.

[0036] Next, the effect of improving the bending stiffness of the wall by discretely arranging the steel pipes in the embodiment of the present invention will be verified. Table 1 shows the ratio of the steel weight per section and the bending stiffness EI per unit width in each of Example 1 (continuous arrangement) and Example 2 (discrete arrangement). In Example 1, steel pipes with a diameter of 1100 mm and a plate thickness of 12 mm were continuously arranged (pitch = steel pipe diameter), and in Example 2, steel pipes with a diameter of 1200 mm and a plate thickness of 12 mm were discretely arranged (pitch > steel pipe diameter) in a section of about 10 m along the extension direction of the wall. The bending stiffness EI and the steel weight ratio are expressed as a ratio of 1 for Example 1 (continuous arrangement). As shown in Table 1, by discretely arranging the steel pipes, when the bending stiffness per unit width is the same, the steel weight can be reduced to about 80%. As explained above with reference to FIG. 5, the larger the steel pipe diameter is, the more the steel weight required to obtain the same bending stiffness EI is reduced, so it is theoretically possible to make the pitch larger relative to the steel pipe diameter. However, in order to maintain uniform rigidity as a wall, it is desirable that the length of the section of the steel sheet pile wall that is skipped due to the increased pitch of the steel pipes, i.e., that does not overlap with the steel pipes in the extension direction of the wall, be limited to the length of one steel sheet pile.

[0037] [Table 1]

[0038] FIG. 7 is a graph showing the results of calculating the load sharing rate of the structure including the first steel pipe row arranged in the extension direction of the wall when the number N of steel pipe sheet piles constituting the second steel pipe row arranged in the direction intersecting the wall is changed for the quay wall structure according to one embodiment of the present invention described above. If a sufficient embedded depth is ensured for the first steel pipe row, the load sharing rate increases as the number N of steel pipe sheet piles constituting the second steel pipe row increases as shown in the graph. By increasing the load sharing rate of the wall including the first steel pipe row and the second steel pipe row, the load borne by the support pile structure and the backing pile structure becomes smaller, and for example, the embedded depth of the support piles can be made shallower and the amount of steel material of members including beams can be reduced.

[0039] Although the preferred embodiment of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person having ordinary knowledge in the technical field to which the present invention pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0040] Reference Signs List 1...quay structure, 2...steel sheet pile wall, 3...first steel pipe row, 31...steel pipe sheet pile, 311...joint, 32...steel pipe pile, 33...connecting member, 4...second steel pipe row, 40, 41, 42, 43...steel pipe sheet pile, 401...joint, 401A...female joint member, 401B...male joint member, 402...filler, 403A...slip stopper, 403B...slip stopper, 431...joint, 5...support pile structure, 51...support pile, 52...jacket leg, 53...fitting member, 6...pile structure, 61...pile, 62...jacket leg, 7...beam, G...ground, W...wall.

Claims

1. a first steel pipe row including a plurality of steel pipe piles connected to the steel sheet pile wall at a portion above the underground portion, and a first steel pipe sheet pile arranged at a ratio of one to the plurality of steel pipe piles and connected to the steel sheet pile wall at a portion above the underground portion, the first steel pipe row being arranged on the sea side of the steel sheet pile wall at intervals that match the unevenness of the planar shape of the steel sheet pile wall; a second steel pipe row in which at least one steel pipe sheet pile including a second steel pipe sheet pile functioning as at least a part of a support pile structure is arranged from the first steel pipe sheet pile toward the sea side in a direction intersecting an extension direction of the steel sheet pile wall; A quay structure equipped with:

2. a first steel pipe row including a plurality of steel pipe piles connected to the steel sheet pile wall at a portion above the underground portion, and a first steel pipe sheet pile arranged at a ratio of one to the plurality of steel pipe piles and connected to the steel sheet pile wall at a portion above the underground portion, the first steel pipe row being arranged along the steel sheet pile wall separately from the steel sheet pile wall at an interval that matches the unevenness of the planar shape of the steel sheet pile wall on the sea side of the steel sheet pile wall; A second steel pipe row in which at least one steel pipe sheet pile including a second steel pipe sheet pile functioning as at least a part of a support pile structure is arranged in a direction intersecting an extension direction of the steel sheet pile wall from the first steel pipe sheet pile; A quay structure equipped with:

3. The quay structure according to claim 1 or 2, further comprising a bund structure located on the seaward side of the support pile structure, and a connecting member connecting the support pile structure to the bund pile structure.

4. The support pile structure includes the second steel pipe sheet pile and a first jacket leg fitted to the outside of a head of the second steel pipe sheet pile, The bail structure includes a bail and a second jacket leg that fits onto an outer side of a head of the bail; The quay wall structure according to claim 3 , wherein the connecting members include a first connecting member disposed between the first jacket leg and the second jacket leg.

5. The support pile structure includes a fitting member that fits into the inside of the head of the first steel pipe sheet pile, The quay wall structure according to claim 4 , wherein the connecting members include a second connecting member disposed between the first jacket leg and the fitting member.

6. 6. The quay wall structure according to claim 4 or claim 5, wherein at the head of the second steel pipe sheet pile, no joint is formed between the second steel pipe sheet pile and an adjacent steel pipe sheet pile, and the first jacket leg is fitted from the outside into the part where no joint is formed.

7. 7. A quay wall structure according to claim 1, wherein a stopper protrudes from a peripheral surface of a steel pipe sheet pile in a joint space enclosed by fitting a joint between the first steel pipe sheet pile and the steel pipe sheet pile included in the second steel pipe row, or between the steel pipe sheet piles included in the second steel pipe row, and the joint space is filled with a filling material.

8. a step of constructing a first steel pipe row by arranging a plurality of steel pipe piles and a first steel pipe sheet pile, one for each of the plurality of steel pipe piles, at intervals that match the unevenness of the planar shape of the steel sheet pile wall on the sea side of the steel sheet pile wall, and connecting the steel sheet pile wall and the first steel pipe row at a portion above the underground portion; A step of connecting at least one steel pipe sheet pile to the first steel pipe sheet pile to construct a second steel pipe row toward the sea side; a step of incorporating a second steel pipe sheet pile included in the second steel pipe row into a support pile structure; A method for constructing a quay structure, comprising:

9. a step of constructing a first steel pipe row on the sea side of the steel sheet pile wall by arranging a plurality of steel pipe piles and a first steel pipe sheet pile, one for each of the plurality of steel pipe piles, along the steel sheet pile wall at intervals that match the unevenness of the planar shape of the steel sheet pile wall, separately from the steel sheet pile wall, and connecting the steel sheet pile wall and the first steel pipe row at a portion above the underground portion; A step of connecting at least one steel pipe sheet pile to the first steel pipe sheet pile to construct a second steel pipe row; a step of incorporating a second steel pipe sheet pile included in the second steel pipe row into a support pile structure; A method for constructing a quay structure, comprising:

10. The step of incorporating the second steel pipe sheet pile into the support pile structure includes a step of fitting a first jacket leg to an outer side of a head portion of the second steel pipe sheet pile, The method for constructing a wharf structure according to claim 8 or claim 9, further comprising a step of driving a backing pile on the sea side of the first steel pipe sheet pile using a second jacket leg connected to the first jacket leg via a connecting member as a guide.

11. installing a first jacket leg, a second jacket leg located seaward of the first jacket leg, and a connecting member connecting the first jacket leg to the second jacket leg; driving a pier using the second jacket leg as a guide; Further comprising:

10. The method for constructing a quay structure according to claim 8 or claim 9, wherein the step of incorporating the second steel pipe sheet pile into a support pile structure includes the step of driving the first steel pipe sheet pile using the first jacket leg as a guide.

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